U.S. Pat. No. 2,253,996 to Bechman for Exercising Device. This patent covers a balance board and actuated by impulse of the feet of the user.
U.S. Pat. No. 3,441,271 to Palacios for Planetary Exercise. This patent covers an exerciser adapted to provide planetary movement to a person standing thereon.
U.S. Pat. No. 3,511,500 to Dunn for Constant Resistance Exercise Device. This covers a beam mounted on an oscillatable shaft, and having adjustable braking means for frictional resistance to the oscillation of said shaft.
U.S. Pat. No. 3,525,522 to Piller for Friction Type Foot Exercising Device. This covers a pair of foot pedals pivotally supported intermediate the ends thereof in a side by side relationship mounted on a shaft.
U.S. Pat. No. 3,598,404 to Bowman for Exercising Apparatus Including Pivotally Connected Weight-Supporting Units. This covers leg calf exercising apparatus comprised of feet retaining platforms for toe-up exercises, and the foot engaging surfaces are disposed at different lateral angles.
U.S. Pat. No. 3,628,791 to Garcia for Pivoted Jogging Platform With Adjustable Spring-Resistance. This covers a jogging device having a pair of pivoted foot pedals or platforms that are yieldingly supported by a spring mechanism.
U.S. Pat. No. 4,270,749 to Hebern for Exercising Device. This covers an exercising device for use by a person in a standing position, and having a planar treadle mounted for a rocking movement about a horizontal axis.
U.S. Pat. No. 4,319,749 to Agyagos for Multiple Exercising Device. This covers an exercising device consisting essentially of a rectangular box having spaced pre set holes into which freely rotatable disks may be inserted to be actuated by the exerciser standing thereon.
U.S. Pat. No. 3,911,907 to Smith for Planetary Exercising Machine. This covers a machine in which the user's legs are simultaneously subjected to cyclic twisting in two directions, while simultaneously the entire lower torso is twisted cyclically. All of this exercising motion is produced by a variable speed drive motor.
None of the above, either singly or collectively, is pertinent art which discloses this present invention of Melby, in view of the fact that only the reference U.S. Pat. No. 3,911,907 to Smith discloses a motor drive, and further this Smith patent discloses a cyclic twisting motion to a person standing thereon, and is not usable by a person in a prone back laying position as disclosed in this present Melby invention.
The above mentioned Smith patent does not disclose reciprocating motion actuating the user's legs, neither is this Smith machine usable in a horizontal position.